Electrically-driven revolving door control circuit



Oct. 4, 1960 A. M. slMPsoN 2,954,971

ELECTRICLLY-DRIVEN REVOLVING DOOR CONTROL CIRCUIT Filed Aug. 30, 1957 2 Sheets-Sheet 1 Oct. 4, 1960 A. M. slMPsoN 2,954,971

ELECTRICALLY-DRIVEN REVOLVING DOOR CONTROL CIRCUIT Filed Aug. 30, 1957 2 Sheets-Sheet 2 J? INVENTOR :F.TE- E BY j ATTORNISY 2,954,971 Patented Oct. 4, 1960 ELECTRICALLY-DRIVEN REVOLVING DOOR CONTROL CIRCUIT Arthur M. Simpson, Evansville, Ind., assignor to Interv national Steel Company, Evansville, Ind., a corporation of Indiana Filed Aug. 30, 1957, Ser. No. 681,290

'5 Claims. (Cl. 268-31) My invention relates :broadly to revolving doors and more particularly to a control circuit for an electricallydriven revolving door system.

My invention relates -to that class of revolving door systems as set forth in my copending application Serial Number 653,917, led April 19, 1957, for Electrically- Driven Revolving Door System.

`One of the objects of my invention is to provide a control circuit for an electrically-driven two-speed revolving door system which is remotely controlled by means of electrical contact oor mats.

Another object of my invention is to provide a control circuit for an electrically-driven revolving door system tfor rotating the revolving l.door at `different speeds during periods of moderate and heavy tratlc and bringing the revolving door to a state of rest during periods when there is no traine.

Still Ianother object of my invention is to provide a control circuit for a revolving ydoor system which makes it possible to convert existing revolving `doors into electrically-driven two-speed revolving door systems.

vStill another object of my invention is to provide a control circuit for a twoamotor, two-speed revolving door system which contains a time `delay relay for controlling the excitation to the high speed motor and another time delay relay for controlling the low speed motor excitation.

A further object of my invention is to provide a control circuit for a two-speed revolving door system for use .at installations where traic is intermittent and where it would not be economical to have the revolving door rotating -at low speed `during extended periods of non-use. v

Other and further objects of my invention are set forth more fully in the specification hereinafter following by reference to the .accompanying drawings, in which:

Fig. 1 is an electrical wiring schematic diagram of the revolving door system control circuit of my invent-ion; v

Fig. 2 is a top elevational view tak-en just below the ceiling line, showing a revolving door in its enclosure and particularly showing the position of the floor contact mats with respect to the revolving door and its enclosure;

Fig. 3 is an enlarged `foreshortened view of a fra-gmentary portion of Fig. 2 showing the relation between the access hole in the revolving `door enclosure frame and the conduit, in which the oor contact mat wires are located;

Fig. 4 is an enlarged foreshortened vertical sectional View taken substantially along .line 4 4 of Fig. 3; and

Fig. 5 is a `fragmentary vertical sectional view taken substantially along line 5-5 of Fig. 4 and particularly showing the spatial relation between the contact mat contact members. 4

My invention is directed to an arrangement of a control circuit Ifor electrically-driven,` two-motor, twospeed, revolving door system of the class as set forth more fully in my copending application Serial Numberl 653,917, led April 19, 1957, for Electrically-Driven' Revolving Door System, supra. The circuit contains two time .delay relays with their coils connected in parallel `and energized by pressure on a oor contact mat. When the revolving door is standing at rest, pressure from a user stepping on one of the floor contact The first time' mats closes both the Itime delay relays. delay relay operates the motor switching or speed change relay to throw the revolving door into high speed operation for three-quarters of a revolution, to enable thel user to pass through the door without having to exert any pressure .against the door. The second time delay relay allows the revolving door to rotate at low speed for approximately three minutes after the end ofthe three-quarters of a revolution operation at high speed,V unless an additional contact is made on the floor mat which will again throw the door into high speed operation for three-quarters of a revolution and reset the The reason for the second time delay relay `is that in some locations such as savings banks or airport e11- trances where .there are long periods of time during the' lday when -there is no trac and thus no one using the revolving door, there is no occasion 4for having the,y

revolving door rotate continually at low speed for a long period of time as does the system as set forth in my copending application filed April 19, 1957, Serial Number 653,917 for Electrically-Driven Revolving Door System, supra. The result is that `during periods of more or less continuous traic the revolving door will operate normally at low speed but will be accelerated to high speed as each person Apasses .through the door. However, when a period of the kday is reached when traic is thinned out and people are not entering the door within a period of approximately three minutes of each other, then the door will stop rotating approxi mately three minutes after the last person passes through the-door. This has the advantage that .during periods of heavy traffic the door is not continually accelerating from a state of rest with excessive wear and tear on the clutch mechanism.- During periods of lthe day when traic is very light the door is stopped .during long in tervals :between the use of the door, and the infrequent operation of the door from rest to high speed at this time is not a serious matter. I desire that it be understood 4that the second time `delay relay may be set for any `desired time delay, but for illustrative purposes I have used al period of approximately three minutes throughout this specification.

Standard type floor contact mats are employed, one type of such pressure contact mats being set forth in this specification.

Referring to the drawings in more detail similar reference characters refer to similar components in the sev-' eral views. j

In Fig. 1, I have shown the electrical wiring schematic diagram of the electrically-driven revolving door control circuitof my invention. The control circuit is substantially contained in housing 1 and consists of control circuit transformer 2, safety relay 3, short time delay relay 4, long time delay relay 5, motor switching relay 6, 24- volt toggle switch 7, and circuit closing oor contact mats 8. Control circuit transformer 2 is energized by excitation voltage applied at terminals 9 and 10; The magnitude of the excitation voltage depends upon the type motors employed to drive revolving door 11. Forexplanation purposes I will use an excitation voltage of 11S-volts, 60 cycles, A C., as an example in this specification. A control voltage in the range of approximately 24volts, for relay excitation, is obtained from the secondlary winding of transformer 2 and is controlled by toggle switch 7 which is inserted in the 24-volt excitation lines.`

When toggle switch 7 is turned to the ON position; 24- volt excitation voltage is applied to the relay circuitry and appears across terminals 12 and 13, and thus across contact members 14 and 15 of circuit closing iloor contact mats 8. No relays are initially energized since cornpletion of the 24-volt relay excitation circuit depends upon electrical contact between members 14 and 15 in one of the two oor contact mats 8. Since the electrical circuits in the contact mats are in parallel, electrical contact between members 14 and 15 in either mat will complete the 24-volt circuit.

The iirst user entering the revolving door makes electrical contact between members 14 and 15 in the floor contact mat over which he passes since only slight pressure is required on the contact mat surface 16 to make electrical'contact between these two members. Thus electrical contact between members 14 and 15 completes the 24-volt relay excitation circuit and is effectively the same as putting an instantaneous short circuit across terminals 12 and 13 since electrical contact between members 14 and 15 exists only during the short period that the users weight is applied to the contact mat surface as he walks over it. When the 24-volt circuit is completed, 24-volt excitation voltage is applied to the coils of short time delay relay 4 and long time delay relay 5, which are connected in parallel, thus energizing both relays and causing their respective movable contact members 17 and 18 to move into contact with iixed cont-act points 19 and 20, respectively. Since movable contact member '18 is connected to one side of the 24-volt excitation line and fixed contact point 20 is connected to one end of the coil of safety relay 3, the safety relay is thus energized as long as the long time delay relay is energized since the other end of the safety relay coil is connected to the other side of the 24-volt excitation line. From the preceding it is seen that long time delay relay 5, when energized, puts the coil of safety rel-ay 3 in parallel with the secondary winding of transformer 2, thus energizing the safety relay. Fixed contact points 21 and 22 of safety relay 3 are connected across the ll-volt transformer excitation lines and when this relay is energized it completes the 11S-volt motor excitation circuit to movable contact members 23 and 24, respectively, of motor switching relay 6. Motor switching relay 6 is controlled by short time delay relay 4. in a manner similar to the manner in which long time delay relay 5 controls safety relay 3. Movable contact member 17 of short time delay relay 4 is connected to one s ide of the secondary Winding of transformer 2. The opposite end of the secondary winding is connected to one end of the excitation coil of motor switching relay 6 while the other end of the coil is connected to xed contact point 19 of short time delay relay 4. Thus, when short time delay relay 4 is energized, movable contact member 17 moves into electrical contact with fixed contact point 19 resulting in putting the coil of motor switching relay 6 in parallel with the secondary winding of transformer 2, thus impressing 24-vo1ts across the relay coil and energizing the relay.

Motor switching relay 6 is a double-pole-double-throw relay with two contacts normally open and two contacts normally closed. Excitation to the low speed motor 25 is supplied through the normally closed contacts when the relay is in the deenergized state and excitation is supplied to high speed motor 26 through the normally open contacts when the relay is in its energized state. When the motor switching relay coil is energized as stated in the preceding paragraph, movable contact members 23 and v24 break the 11S-volt excitation circuit to the low speed motor 25 and complete the 11S-volt excitation circuit to the high speed motor 26, thus rotating the revolving door 11 through mechanical linkage system 27 from a state of rest. One type of such overhead mechanical drive and linkage systems is set forth fully in my copending application Serial Number 653,917, filed April 19, 1957, for Electrically-Driven Revolving Door System. From the above description it can be seen that when toggle switch 7 is turned to the ON position the first user making contact with a contact mat, immediately energizes the revolving door high speed motor and starts the revolving door rotating at a speed of approximately eight or nine revolutions per minute from a state of rest.

Short time delay relay 4 and long time delay relay 5 `are of the type that will deenergize themselves after a certain period of time has elapsed from the moment they were energized and the length of the time period is adjusted according to requirements. Short time delay rev lay 4 is set so that it will deenergize itself and thus dropout after the period of time has elapsed that it takes the revolving door to rotate three-quarters of a revolution when driven by the high speed motor. This is more than sufficient time `for the user to pass through the revolving door. Long time `delay relay 5 is set so that it will deenergize itself and thus drop-out after approximately three minutes has elapsed from the time the relays were energized, When the relays are energized by pressure on one of the contact mats 8 the door will begin to rotate, since it is driven by high speed motor 26, at a speed of eig-ht or nine r.p.m. from a state of rest, and will rotate at this rate of speed for 270 degrees or three-quarters of a door revolution, thus allowing the user to pass through the door at which time short time delay relay 4 will deenergize and thus drop-out. When this occurs, motor switching relay 6 will deenergize since the circuit to its coil is interrupted thus causing movable contact members 23 and 24 to break the 11S-volt excitation circuit to high speed motor 26 and complete the 11S-volt excitation circuit to low speed motor 25 resulting in the revolving door being driven at a lower rate of speed by the low speed motor. The low speed motor will rotate the revolving door at an idling speed of approximately three or four r.p.m. until three minutes have elapsed from the moment the relays were energized at which time long time delay relay 5 will deenergize itself, thus interrupting the coil circuit of safety relay 3 causing it to deenergize and drop-out, resulting in interrupting the 11S-volt motor excitation circuit, thus removing excitation voltage from movable contact members 23 and 24 of relay 6 and the low speed motor, causing the revolving door to return to a state of rest until the next oor mat contact is made.

At each contact made between members 14 and 15 of contact mats 8 both time delay relays are reset and their time before drop-out period begins to run over again. Therefore, if there are a lseries of consecutive contacts of the contact mats without a three minute interval intervening between any of the contacts the revolving door will not stop rotating until about three minutes have elapsed from t-he last Hoor mat contact or after the last person passes through the door. During the above series of consecutive floor mat contacts the door may be switching yback and forth between high speed operation and low speed operation. If traiiic through the door is particularly -hcavy it is possible that the revolving door may be operating at high `speed the greater part of the time if a steady stream of people enter, one right after the other so that a new user has made contact with a floor mat before the door has had a chance to rotate a complete 270 degrees since the last user made contact with a contact mat.

Referring to the several remaining views reference character 28 designates the revolving door enclosure. Wires 14 and 1S' connected to contact members 14 and 15, respectively, in floor contact mat 8 are laid in conduit 29 in licor 30 and gain access to terminals 12 and 13, respectively, of housing 1 through floor cavity 31 and access hole 32 in revolving door enclosure 28. Floor Contact mat 8 is laid in angle frarne 33 to which conduit 29 is welded for support. Floor contact mat 8 substantially consists of electrically conductive contact members 14 and 15 spatially separated by strips 35 of resilient insulation material suc-h `as rubber and entirely encased within a protective sheathing 34 of resilient insulation material such as rubber. Contact member 14 is a ribbed member with -said ribs spaced by resilient insulation strips 35, so that they `are in close proximity to contact member 15. When pressure is applied to floor mat surface 16 the resilient insulation strips 35 between the two contact members compress under this pressure and allow the ribs of contact member 14 to make electrical contact with contact member 15, thus completing the electrical circuit as previously described. When the pressure is removed from floor mat surface 16 the restoring action of the resilient insulation material of strips 35 separates the ribs of contact member 14 and contact member 15, thus interrupting the electrical contact between the two members.

While I have described my invention in certain embodiments, I realize that modifications may be made, and I desire that it be understood that no limitations upon my invention are intended, except as may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent tof the United States is as follows:

1. A revolving door system comprising a power source, two different electric motors, one of said motors operating at a higher speed than the other of said motors, separate time delay circuits associated with each of said motors, a revolving door Wing assembly mounted Ifor rotation for the admission of individuals through a revolving door entrance way, means for driving said revolving door wing assembly through both of said motors, and an electric circuit controller operative by individuals passing through the revolving door wing assembly for controllingthe application of said power source to both of said motors through said time delay circuits for driving said revolving door wing assembly from a condition of rest to a rate of speed initially determined by the speed of rotation of said higher speed motor and means controlled by said time delay circuits for interrupting the energization of said higher speed motor while maintaining the energization of the lower speed motor for a time period determined by the operation of the time delay circuit associated with said lower speed motor.

2. A revolving door system las set forth in claim 1, in which said separate time delay circuits include a Short time 4del-ay relay and a long time delay relay each having operating windings controlling contactors for applying power from said power source to said electric motors and circuits extending from said windings to said electric circuit controller.

3. A revolving door system as set forth in claim 1, in which said separate time delay circuits each includes a short time delay relay and `a long time delay relay and each of said relays including operating windings and contactors where said operating windings are connected in parallel and are simultaneously controlled by said electric circuit controller, said contactors being connected with the respective electric motors.

4. A revolving door system as set forth in claim 1, in which said separate time delay circuits include a short time delay relay and a long time delay relay each having operating windings and contactors, `said operating windings being connected in parallel and circuits controlled by said contactors leading to the respective motors, the contactors of said long time delay relay remaining closed to complete circuits to the lower speed motor for a time period longer than the time period during which said higher speed motor is energized under control of the contactors of said short time delay relay.

5. A revolving door system as set forth in claim 1 including a safety relay circuit, means for initiating said safety relay circuit in operation upon application of power to each of said motors, and means associated with said safety relay circuit for interrupting power to said motors after the lapse of a predetermined time limit.

References Cited in the tile of this patent UNITED STATES PATENTS 1,015,491 Haviland Jan. 23, 1912 1,134,325 Flint Apr. 6, 1915 2,267,632 Wunsch Dec. 23, 1941 2,341,545 Hagenbook Feb. 15, 1944 2,511,793 Telbizoff June 13, 1950 

